Immune Deficiency

Immunodeficiency (or immune deficiency) is a state in which the immune system's ability to fight infectious disease and cancer is compromised or entirely absent. Most cases of immunodeficiency are acquired ("secondary") due to extrinsic factors that affect the patient's immune system.

Most of the time, the immune system protects the body from germs and other threats. But sometimes it gets off track and has a weaker response to these threats. This low activity is called immune deficiency and it makes you less able to fight off infections. It can result from medications or illness. Or it may be present from birth -- a genetic disorder known as primary immune deficiency.